Thermometer utilizing tension of vapors.



J. B. FOURNIER.

THERMOMETER UTILIZING TENSION OF VAPORS.

APPLICATION FILED MAY 3, 1909.

' Patented July 4, 1911.

M ma; 554% ff -13:

UNITED STATES PATENT o Fm.

JOSEPH BARBE FOURNIER, OF PARIS, FRANCE.

THERMOMETER UTILI ZING TENSION 0F, VAZ PORS.

To all whom it may concern: r 4

Be itknown that I, J OSEPH 'BARBE FOUR- NIER, a citizen of the French Republic, and resident of Paris, France, have invented certain new and useful Improvements in' Thermomete s of which the following is a specification.

The thermometers based upon the law of the tension of saturated vapors and particularly those which have to transmit or register at a distance the temperatures, must-have only one part which is sensitive to the'heat, viz. :the plunging reservoir or explorer which is placed in the chamber or at the spot whose temperature is to be measured'or registered. It is important that the sensitive substance, that is to say, the substance 'whosc vapor serves to measure by its pressure the temperature, be prevented from escaping from the explorer reservoir. 1th

this object in view this substance must not frequent applications of the invention with which it is almost impossible to choose the sensitive substance and the motor fluid so that they answer the above stated conditions and requirements.

This invention has for its object to obviatethis inconvenience by interposing in the explorer reservoir between the substance which is sensitive to the heat and the motor fluid an intermediate substance which separates said two substances and which possesses the property required of being absolutely withoutany influence upon either of said substances. With this object in view the explorer reservoir is divided into two compartments so that the sensitivesubstance or its vapor is preventedfrom penetrating into the one of said compartments, the motor fluid being prevented from penetrating into the other compartment. In this manner any contact between the sensitive substance and the motor fluid is rendered impossible. This invention therefore renders it possible to considerably extend the applications of these apparatuses and the limits of their functions. It especially renders it possible to use a gas as motor fluid and consequently to realize vertical transmissions at very great heights or depths. In fact, if the manometer is placed at the same level as the explorer reservoir the weight of the Specification pf Letters Patent.

Utilizing the Tension of Vapors,

. part.

- Patented July 4, 191 1.

.\ A icationfilea ma a, 1909. Serial No. 493,661.

column so that the indications of the manometer cease .to 'be sufliciently perceptible; therefore, it would be impossible to employ an apparatus .of the ordinary type for indieating at the surface of the earth' the temperature which prevails in the pit of a mine or for indicating at the foot of a mountain the temperature which prevails at its summit, and so forth. This invention further renders it possible to reduce the explorer reservoir to the volume of a capillary tube and consequently to realize instantaneous transmissions of the temperature.

In the accompanying drawing the preferred form of the invention is shown by way of example.

Figures}, 2 and 3 represent thermometers designed for the instantaneous indication of temperatures. J a

The improved thermometer consists of a capillary tube 6 closed at its lower end. This capillary tube serves as explorer atits lower closed end and as transmitter at its upper In the lower end of the capillary tube a sufficient quantity of sensitive substance h is contained and further a sulhcient quantity of intermediary substance 70, said substances being separated by an empty space m. Thewhich has to be indicated by the apparatus.

2.-It must not have any chemical influence upon either the sensitive substance '72. or the tive'substance h and of the transmitter sub- 7 stance i. The sensitive substance h and the motor liquid i can therefore never 'come in contact. The substances h and a may therefore be of such a nature that they would otherwise combine, dissolve the one the other,

- admin or diffuse the one in the other. By

way of example anilin is cited as a suitable 7 sensitive substance h, glycerin as a suitable motor liquid 11 and v the fusible alloy Dracet melting at 9( C. asfintermediary substance 70.

Owing to the small diameter of the tube 6 the capillary forces are sufiicient to maintain the intermediary substance is between the sensitive substance h and the motor sub.- stance 2' so that these latter two substances are always separated by the intermediary substance is. In this manner an explorer of very small dimensions is obtained which is adapted to come very quickly to an equilibrium of temperature with the thermic spot be 4 wound to form a spiral asshown in Fig. 2,

into which it is plunged.

The cap1llary-reservo1r can, of course,

the intermediary substance lcbeing imprisoned in this spiral so thatrwithin the limits of the function of the apparatus it never gets out of said spiral; under these conditions the sensitive part of the apparatus will always be limited to* the spiral. Instead of .being'helicoidal as in Fig. 2, the said spiral could be plane as shown in Fig. 3 and soldered upon a metal plate 'g which, being thin and flexible, is adapted to be applied upon a curved surface. An apparatu'sof this type enables the observer to instanta neously ascertain the temperature of such a surface.

As the improved thermometers have the object totlocalize' at a determined the apparatus the vapor chamber which constitutes the sensitive part, instead of the three di-iferentsubstances namely the sensitive substance, the intermediary substance an'dthe motor substance, only one single substance could be used for all three purposes. In this case the liquid substancewould serve at the same time as transmitting and "as sensitive substance and the transmitting tube 6 Apparatus for transmittin' at a distance by means of the pressure of saturated'vapors, comprising in combination the explorer reservoir consisting of a capillary tube, the sensitive substance situated at the lower endof saidcapillary tube, the intermediary substance which becomes liquid at would form the explorer reservoir.

the temperature (at which the apparatus part of 

